com.gumballtools/check-digit

up checked 2026-11-11T03:38:29.395Z

Unclaimed · Unverified

Publisher-provided title

Check Digit Validator

Publisher-provided description

Validates IBAN/ISBN/EAN/Luhn checksums and finds the one wrong digit

Summary by lookupd

Checks checksum validity for IBAN, ISBN, EAN, UPC and Luhn numbers and suggests which digit is likely wrong on failure.

Install

Claude Code, remote (streamable-http)

claude mcp add --transport http check-digit https://check-digit.gumballtools.com/api/mcp

Codex, remote (streamable-http)

codex mcp add check-digit --url https://check-digit.gumballtools.com/api/mcp

Cursor, remote (streamable-http) → .cursor/mcp.json

{
  "mcpServers": {
    "check-digit": {
      "url": "https://check-digit.gumballtools.com/api/mcp"
    }
  }
}

Other clients: docs. Or tell your agent: Set up lookupd for me: read https://lookupd.com/agent.md and follow it.

Publisher-provided text

run Validate the check digit(s) on an IBAN, ISBN-10, ISBN-13, EAN-13, UPC-A, or Luhn-checked card number, and when it fails, try to say which digit is wrong. Use t

Shows this live status and links here; updates hourly.

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